Improvement in balanced valves



' UNITEDSTA Es PATENT OFFICE.

WILLIAM J. WESTWOOD, OF SOUTH BEND, INDIANA..

] :IMPR'OVE'MYENT IN BALANCED VALVES.

V Specification forming part of Letters Patent No. 172,808, dated J anuary'25, 1876; application filed. August 27, 1-575. I 5 1 l To all whom it may concern:

Be it known that I, WILLIAM J. WEST- WOOD, of South Bend, in the county of St. Joseph and State of Indiana, have invented new and useful Improvements in Balanced Slide-Valves; and 1 do hereby declarethat the following is a full and exact description of the same, reference being hadto the accompanying drawings, and to the-letters of reference marked thereon.

The object of my invention is the production of a balanced slide-valve, wherein the live steam is admitted under the valve through the port generally used as the exhaust, which will prevent the live steam from lifting the valve off from its seat, and greatly lessen the friction of such valve.

My invention therein consists in the peculiar form of the spring-plate; further, in the combination of the peculiar spring-plate, the valve having an arched top, and having the live steam admitted under such valve, the valve-chest cover, and the set-screws bearing upon the spring-plate near its ends; and, further, in the combination of the operative parts, all as more fully hereinafter explained.

To enable others skilled in the art to make and use my invention I now proceed to describe the'same in connection with the drawings, in which- Figure l is a side elevation; Fig. 2, a longitudinal section 5 Fig. 3, a top view, with the valve-chest, cover, and spring-plate removed;

Fig. 4, an enlarged top view of the valve and stem, with the rollers removed. Fig. 5 is an enlarged bottom view of the same, and Fig. 6 a separate view of the spring-plate.

Similar letters denote corresponding parts in each figure.

A represents the cylinder. 0 G are two ports, which open out of the cylinder, one at each end thereof, and by means of pipes 0 extending along the top of the cylinder, give communication to the valve seat plate D, where they open into the valve-chest E, one at each end of such valve-chest, through ports 0 and 0 Opening into the valve-chest, be-

tween the ports 0 and O is the steam-port F, which connects by a pipe, F extending down on the outside of the cylinder, with the steam-pipe F On the plate D rests the valvechest E. G is the cover to the valve-chest, and is held to said valve-chest, and the valvechest in turn secured to the cylinder by suit-l able bolts a, which pass down through the four corners of the cover and valve-chest into the plate D. Through the top'of the cover G is secured the exhaust-pipe H. l

I is the valve, made to'fit closely in the chamber of the valve-chest, and rub'against its sides. 7 square in outline,and is fitted and polished, so as to slide easily on its seat upon the plate D. This valve is cast, and has a rectangular recess, 12, in its bottom surface, hollowed out in one direction in the arc of a circle. The top of the valve 0 is formed, in general outline, on

bearing upon the spring-plate near its ends.

These set-screws are provided with lookingnuts 0. The plate K is made just large enough to fit into the valve-chest without turning. The set-screws L press upon the plate near its ends, so that the valve will have a very slight movement vertically to lessen the friction on the valve-seat. The upper surface of the valve being arched, and the rollers raising the spring-plate above the said upper surface 0,

allow the spring-plate to be pressed by the set-screws down at each end without interfering with the movement of the valve. Thus the valve can be kept down to its seat against the upward pressure of the steam, the rollers greatly lessening the friction.

The form of the spring-plate prevents it from turning in the valve-chest, and also allows it to spring slightly at the center when the steam presses the valve upwardly. Being small at the center, where it crosses the mouth of the exhaust-pipe H, it allows the exhauststeam to pass up freely on either side of its central portion. The mouth of the exhaust is The bottom face b of the valve is w preferably made a little flaring, so that the springplate neednot be made too narrow. It can be made "ery cheaply by cutting it from sheet-steel of the right thickness. 7

M is the valve-stem, passing through suitable stuffing-boxes in valve-chest, and connected to the valve by a peculiar connection, which I shall now describe.

The valve has cast on its upper face, projecting upwardly from one edge, two lugs, f, which form a chamber, f, back of them in the Valve. The valve-stein M has a screw-thread, g, cut on its end, and extending a short distance along the stem. The valve-stem is passed through the stuffing boxes and a nut, 9 screwed on, leaving its end clear. The end of the stem is then inserted between the lugs into the Ghamberf, and has a nut, g turned on its end. The nut g is then turned back, locking the nut 9 and keeping the valve-stem rigidly in place.

The live steam is admitted through the pipes F F in the direction of the arrow, into the part F under the valve, where it passes through one of the ports or O and one of the pipes (J (as the valve may be situated) into the cylinder. The exhaust passes from the cylinder through the other pipe 0 up through the other port, over the valve, and into the pipe H. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The spring-plate K, consisting of the central portion at and transverse end pieces d d,

live steam is admitted under the valve, the

combination of the valve Lhaving an arched top, thevalve-chest cover G, the rollers c, the spring-plate K, and the set-screws L, the said set-screws bearing upon the said spring-plate near its ends, when the several parts are constructed and arranged to operate substantially as described-and shown.

This specification signed and witnessed this 5th day of July, 1875.

WILLIAM J. WESTWOOD.

Witnesses:

W. F. PALMER, J AOOB MARTIN. 

